1. Field of the Invention
The present invention relates to a data analysis apparatus and a data analysis method for evaluating a maintenance strategy for a plurality of devices.
2. Related Art
Some of devices operating in various environments are regularly inspected by maintenance persons for state of degradation and the results of such device inspections are accumulated as electronic data. By analyzing data obtained from periodic inspections, it is possible to optimize a maintenance strategy, such as to predict future degradation and decide appropriate timing of replacement.
Optimization of the maintenance strategy includes optimization of timing for replacing individual devices as well as a viewpoint of optimizing global maintenance strategy, such as the interval of periodic inspections of devices and/or criteria for device replacement. Optimization of the latter requires data analysis for estimating how safety will change if a maintenance strategy which is different from one implemented at the time of data collection is implemented.
The invention disclosed in JP-A 2005-296321 (Kokai) that relates to an inspection apparatus and inspection method for fire facilities shows an analysis method for periodic inspection data for predicting degradation of devices based on results of periodic inspections of fire facilities and deciding an appropriate time to replace each of the devices. However, the invention does not show a data analysis method for optimizing periodic inspection times and the like by use of periodic inspection data obtained.
Periodic inspection data is accumulated by maintenance persons in accordance with a certain maintenance strategy (e.g., time of inspection and/or conditions for replacement). It is sometimes desired to analyze accumulated periodic inspection data to predict what happens if the initial inspection is delayed by half a year, for example. If the maintenance cost and/or safety of the current maintenance strategy can be calculated by analyzing obtained data and those of a strategy which delays the initial inspection by half a year can also be calculated, it is possible to determine which one of the strategies is preferable, which can lead to optimization of the maintenance strategy.
That is, it is required to realize evaluation of a maintenance strategy that is different from one which was implemented at the time of data collection. Such analysis is difficult in that a valid result cannot be obtained unless the fact is considered that devices which have been replaced in an inspection under a maintenance strategy under which data was collected may exist without being replaced under a maintenance strategy to be evaluated. It is accordingly required to evaluate a maintenance strategy taking into consideration case examples of devices that have been replaced under a maintenance strategy under which data was collected.